1. Field of the invention
The present invention relates to blades for gas turbine engines and to the means for fixing these blades.
More precisely, the invention relates to a stemmed blade for flow-straightening blading of a gas turbine engine, the blade comprising at least one shank at its head forming a stem intended for the fixing of the said blade.
2. Summary of the prior art
In general, the blades of a flow straightener are fixed at their head to the outer casing of the gas turbine engine, and their inner ends are interconnected by internal annular members defining the inner profile of the active fluid flow path and ensuring a seal with the rotor of the engine.
It is known practice to connect several blades rigidly together on a common sector forming part of the annular member, the blades having threaded radial shanks integral with the heads of the blades and designed to pass through corresponding holes provided in the outer casing of the engine. These shanks serve to fix the blades through cooperation with nuts. The disadvantage of this method of fixing is that it involves high production costs and, in the event of the deterioration of a blade, necessitates dismantling a whole sector of blades.
Also known are rotor blades which comprise studs at their heads intended for the fixing of an outer ring. In this regard U.S. Pat. No. 2 197 335 shows segments capping the blades and fixed to them by bushes and crushing of the studs. The application of this technique to the fixing of the blades of a flow straightener stage to the outer casing of the gas turbine engine would necessitate special tooling for crushing the studs.